Electronic component-embedded printed circuit board

ABSTRACT

Disclosed herein is an electronic component-embedded printed circuit board including: a base plate including an insulating resin layer and circuit layers; and an electronic component embedded in the insulating resin layer, wherein the insulating resin layer has a thickness 1.3˜3 times greater than that of the electronic component. The electronic component-embedded printed circuit board has an optimum thickness ratio of its constituents in order to minimize the warpage thereof at the time of manufacturing the same.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2009-0023449, filed Mar. 19, 2009, entitled “A printed circuit boardcomprising a electronic component”, which is hereby incorporated byreference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic component-embeddedprinted circuit board, and, more particularly, to an electroniccomponent-embedded printed circuit board, which is not warped.

2. Description of the Related Art

Recently, as part of the next-generation multifunctional small-sizedpackaging technology, the development of a semiconductor chip embeddedprinted circuit board has attracted considerable attention.

A semiconductor chip embedded printed circuit board ishighly-functionalized as well as multi-functionalized and miniaturized,because it provides an expedient which can improve a reliability problemoccurring in the course of wire-bonding flip chips or ball grid arrays(BGAs) or in the course of electrically connecting semiconductor chipsusing a solder ball.

Various methods and designs for thinly fabricating such a semiconductorchip embedded printed circuit board have been developed, but there is aproblem in that a warpage phenomenon cannot be overcome and thus themass production thereof is practically difficult.

FIG. 1A is a sectional view showing a conventional semiconductor chipembedded printed circuit board, and FIG. 1B is a drawing showing a realsample of the printed circuit board manufactured using a conventionaltechnology.

As shown in FIG. 1A, the conventional semiconductor chip embeddedprinted circuit board is composed of an insulating layer 1, asemiconductor chip 3, circuit layers 7 and 9 and an bonding layer 5,which have thermal expansion coefficients different from each other, sothat it is difficult to maintain the balance of thermal expansioncoefficients.

Accordingly, in the case where a semiconductor chip embedded printedcircuit to board is manufactured through a conventional method, as shownin FIG. 1B, the printed circuit board is warped due to the unbalance ofmaterial properties and thermal expansion coefficients of thecomponents. When the printed circuit board is warped, subsequentprocesses (for example, a circuit forming process, a laser processingprocess, and the like) cannot be performed, so that it must be discardedor must be manually processed, with the result that the mass productionthereof becomes difficult.

Meanwhile, Japanese Unexamined Patent Application Publication No.2003-127990 discloses a method of manufacturing a semiconductor deviceembedded printed circuit board in which an insulating layer made ofprepreg and resin is embedded with a semiconductor device. However, thismethod also cannot overcome the above problem that a printed circuitboard is warped in the manufacturing method thereof.

Therefore, technologies for preventing the warpage of the semiconductorchip embedded printed circuit board are required.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve theabove-mentioned problems, and the present invention provides anelectronic component-embedded printed circuit board, which canremarkably reduce the warpage thereof.

An aspect of the present invention provides an electroniccomponent-embedded printed circuit board comprising: a base plateincluding an insulating resin layer and circuit layers; and anelectronic component embedded in the insulating resin layer, wherein theinsulating resin layer has a thickness 1.3˜3 times greater than that ofthe electronic component.

In the electronic component-embedded printed circuit board, the circuitlayers may include an upper circuit layer formed on the insulating resinlayer and a lower circuit layer formed beneath the insulating resinlayer, the insulating resin layer may have a thickness 3˜22 timesgreater than that of the upper circuit layer, and the upper circuitlayer may have a thickness 1.1˜2.6 times greater than that of the lowercircuit layer.

The electronic component-embedded printed circuit board may furtherinclude: an adhesion layer interposed between the electronic componentand the lower circuit layer, wherein the insulating resin layer has athickness 3˜9 times greater than that of the adhesion layer.

In the electronic component-embedded printed circuit board, the uppercircuit layer and the lower circuit layer may be made of copper, and theinsulating resin layer 700 may be made of an epoxy resin including O—H,N—H, C—H, C—O and ester groups.

The electronic component may be a silicon semiconductor device.

The adhesion layer may be formed of any one selected from among a dieattach film (DAF), an anisotropic conductive film (ACF), anon-conductive film (NCF), an anisotropic conductive adhesive (ACA) andnon-conductive adhesive (NCA).

Another aspect of the present invention provides an electroniccomponent-embedded printed circuit board including: a base plateincluding a prepreg having a space for mounting an electronic component,an insulating layer having a resin layer applied on the prepreg andcharged in the space, and circuit layers; and an electronic componentmounted in the space, wherein the prepreg has a thickness 1.1˜2.5 timesgreater than that of the electronic component, and the resin layerapplied on the prepreg has a thickness 0.2˜2.5 times greater than thatof the electronic component.

In the electronic component-embedded printed circuit board, the circuitlayers may include an upper circuit layer formed on the insulating layerand a lower circuit layer formed beneath the insulating layer, theinsulating layer may have a thickness 3˜22 times greater than that ofthe upper circuit layer, and the upper circuit layer may have athickness 1.1˜2.6 times greater than that of the lower circuit layer.

The electronic component-embedded printed circuit board may furtherinclude: an adhesion layer interposed between the electronic componentand the lower circuit layer, wherein the insulating layer has athickness 3˜9 times greater than that of the adhesion layer.

In the electronic component-embedded printed circuit board, the resinlayer may be made of a silicon epoxy hybrid resin including NH, CH, SiH,an aromatic ring, CO, Si—O—Si and Si—O—C, or an epoxy resin.

The electronic component may be a silicon semiconductor device.

The insulating layer may have a thickness 1.2˜2 times greater than thatof the prepreg.

The adhesion layer may be formed of any one selected from among a dieattach film (DAF), an anisotropic conductive film (ACF), anon-conductive film (NCF), an anisotropic conductive adhesive (ACA) andnon-conductive adhesive (NCA).

Various objects, advantages and features of the invention will becomeapparent from the following description of embodiments with reference tothe accompanying drawings.

The terms and words used in the present specification and claims shouldnot be interpreted as being limited to typical meanings or dictionarydefinitions, but should be interpreted as having meanings and conceptsrelevant to the technical scope of the present invention based on therule according to which an inventor can appropriately define the conceptof the term to describe the best method he or she knows for carrying outthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will to be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a sectional view showing a conventional semiconductor chipembedded printed circuit board;

FIG. 1B is a drawing showing a real sample of the printed circuit boardmanufactured using a conventional technology;

FIG. 2 is a sectional view showing an electronic component-embeddedprinted circuit board according to an embodiment of the presentinvention;

FIG. 3 is a sectional view showing an electronic component-embeddedprinted circuit board according to another embodiment of the presentinvention;

FIGS. 4 to 8 are sectional views showing a process of manufacturing theelectronic component-embedded printed circuit board shown in FIG. 2;

FIGS. 9 to 13 are sectional views showing a process of manufacturing theelectronic component-embedded printed circuit board shown in FIG. 3; and

FIG. 14 is a drawing showing a real sample of the electroniccomponent-embedded printed circuit board shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the attached drawings. Throughoutthe accompanying drawings, the same reference numerals are used todesignate the same or similar components, and redundant descriptionsthereof are omitted. In the following description, the terms “upper”,“lower”, “first”, “second” and the like are used to differentiate acertain component from other components, but the configuration of suchcomponents should not be construed to be limited by the terms.

FIG. 2 is a sectional view showing an electronic component-embeddedprinted circuit board according to an embodiment of the presentinvention.

As shown in FIG. 2, an electronic component-embedded printed circuitboard according to this embodiment of the present invention includes: abase plate including an insulating resin layer 700 and circuit layers150 and 350; and an electronic component 500 embedded in the insulatingresin layer 700.

Here, the insulating resin layer 700 may be made of, but not limited to,an epoxy resin including O—H, N—H, C—H, C—O and ester groups, and theelectronic component 500 may be a semiconductor device.

In this case, in order to minimize the warpage of a printed circuitboard, the thickness (D1) of the insulating resin layer 700 may be 1.3˜3times that (D4) of the electronic component 500.

The thickness ratio of the insulating resin layer 700 and the electroniccomponent 500 is determined by various experiments in which the thermalexpansion coefficients of the materials used for the insulating resinlayer 700 and the electronic component 500 are considered. That is, itis experimentally proved that an electronic component-embedded printedcircuit board which is very difficult to warp can be obtained, when thethickness (D1) of the insulating resin layer 700 is 1.3˜3 times that(D4) of the electronic component 500. When the thickness (D1) of theinsulating resin layer 700 is less than 1.3 times that (D4) of theelectronic component 500, the electronic component 500 can be easilybroken at the time of lamination of the electronic component 500. Incontrast, when the thickness (D1) of the insulating resin layer 700 ismore than 3 times of that (D4) of the electronic component 500,subsequent processes cannot be performed because the warpage of theprinted circuit board become serious, and the electrical properties ofthe printed circuit board deteriorate because the length of a micro viais increased at the time of forming a via in the insulating resin layerthrough laser processing. Hereinafter, the experimental results thereofwill be described.

In this embodiment, the circuit layers 150 and 350 include an uppercircuit layer 350 formed on the insulating resin layer 700 and a lowercircuit layer 150 formed beneath the insulating resin layer 700. Thesecircuit layers 150 and 150 may be made of an electroconductive metal,such as gold (Au), silver (Ag), copper (Cu), nickel (Ni) or the like,preferably copper, and more preferably low profile copper or very lowprofile copper.

In this case, the thickness (D2) of the upper circuit layer 350 may be1.1˜2.6 times that (D3) of the lower circuit layer 150. The uppercircuit layer 350 is generally formed by etching and plating a resincoated copper (RCC) foil. Since the resin coated copper (RCC) foil hasalready received thermal hysteresis in the preparation process thereof,it has different tension from that of a copper foil constituting thelower circuit layer 150, whose copper foil did not receive the thermalhysteresis. Therefore, when these RCC foil and copper foil are designedto have the same thicknesses, it causes warpage of panel. Further, ifthe thickness (D2) of the upper circuit layer 350 is less than 1.1 timesor more than 2.6 times of that (D3) of the lower circuit layer 150, theupper circuit layer 350 and lower circuit layer 150 are independentlywarped, and thus it is impossible to really design them.

Meanwhile, it is verified that when the thickness (D1) of the insulatingresin layer is 3˜22 times that (D2) of the upper circuit layer 350, thewarpage of a printed circuit board can be reduced.

Further, the electronic component-embedded printed circuit boardaccording to this embodiment of the present invention may furtherinclude an adhesion layer 530 interposed between the electroniccomponent 500 and the lower circuit layer 150. The adhesion layer 530serves to fix the electronic component 500 on the lower circuit layer150 during a process of manufacturing a printed circuit board. Theadhesion layer 530 may be formed of any one selected from among a dieattach film (DAF), an anisotropic conductive film (ACF), anon-conductive film (NCF), an anisotropic conductive adhesive (ACA) andnon-conductive adhesive (NCA), and may include an epoxy resin.

In this case, the thickness (D1) of the insulating resin layer 700 maybe 3˜9 times that (D5) of the adhesion layer 150, and the thickness(represented by “D1−(D4+D5)”) of the insulating resin layer 700 locatedon the electronic component 500 may be 0.1˜0.7 times that (D1) of thetotal insulating resin layer 700.

Table 1 shows experimental result data for obtaining the thickness ratioof the respective constituents of the printed circuit board according tothis embodiment. As shown in Table 1, the optimum thickness ratio of theprinted circuit board can be obtained by measuring whether a printedcircuit board is warped or not while changing D1˜D5. In Table 1, thethickness (D1) of the insulating resin layer 700 is defined as 100, andthe thickness ratio of other constituents thereof is represented inpercentages to the thickness (D1).

Although Table 1 shows only representative experimental data for thepurpose of explaining an experimental method, many experiments wasconducted using other experimental data not shown in Table 1 in order toobtain the thickness ratios of the constituents defined in the presentinvention. Since Table 1 discloses the representative experimental datawithin the range in which the feature of the present invention is notobscured, the scope of the present invention is not limited to theexperimental values shown in Table 1.

TABLE 1 Thick- Thick- Thickness Thickness ness ness of of of upper oflower electronic Thickness insulating circuit circuit com- of die layerlayer layer ponent attach film Warpage No. (D1) (D2) (D3) (D4) (D5)occurrence 1 100 28 25 63 35 x 2 100 29 26 66 26 x 3 100 27 21 69 27 x 4100 4 4 50 19 ∘ 5 100 13 13 75 25 ∘ (units: %)

FIG. 3 is a sectional view showing an electronic component-embeddedprinted circuit board according to another embodiment of the presentinvention. Here, the description duplicating that of the aboveembodiment will be omitted.

As shown in FIG. 3, an electronic component-embedded printed circuitboard according to this embodiment of the present invention includes: abase plate including an insulating layer and circuit layers 150 and 350;and an electronic component 500 embedded in the insulating layer.

In this embodiment, the insulating layer may further include a prepregprovided therein with a space for mounting the electronic component 500;and a resin layer 730 applied on the prepreg 600 and charged in thespace.

In this embodiment, the resin layer 730 may be made of, but not limitedto, a silicon epoxy hybrid resin including NH, CH, SiH, an aromaticring, CO, Si—O—Si and Si—O—C or only an epoxy resin. The prepreg 600 maybe made of a resin impregnated with a reinforcing material such as glassfiber or the like, and the electronic component 500 may be a siliconsemiconductor device.

In this case, in order to reduce the warpage of an electroniccomponent-embedded printed circuit board, the thickness (D6) of theprepreg 600 may be 1.1˜2.5 times that (D4) of the electronic component500, and the thickness (D7) of the resin layer 730 applied on theprepreg 600 may be 0.2˜2.5 times that (D4) of the electronic component500. The thickness ratio of the prepreg 600, the insulating layer 730and the electronic component 500 is determined by various experiments inwhich the thermal expansion coefficients of the materials used for theprepreg 600, the insulating layer 730 and the electronic component 500are considered.

In this case, the total thickness (D1) of the insulating layer may be1.2˜2 times that (D6) of the prepreg 600, and the thickness (representedby “D1−(D4+D5)”) of the resin layer 730 located on the electroniccomponent 500 may be 0.1˜0.7 times that (D1) of the total insulatinglayer.

In this embodiment, the circuit layers 150 and 350 include an uppercircuit layer 350 formed on the insulating layer and a lower circuitlayer 150 formed beneath the insulating layer. These circuit layers 150and 350 may be made of an electroconductive metal, such as gold (Au),silver (Ag), copper (Cu), nickel (Ni) or the like, preferably copper,and more preferably low profile copper or very low profile copper. Inthis case, the thickness (D2) of the upper circuit layer 350 may be1.1˜2.6 times that (D3) of the lower circuit layer 150.

Further, in order to reduce the warpage of a printed circuit board, thethickness (D1) of the insulating layer may be 3˜22 times that (D2) ofthe upper circuit layer 350.

Meanwhile, the electronic component-embedded printed circuit boardaccording to this embodiment of the present invention may furtherinclude an adhesion layer 530 interposed between the electroniccomponent 500 and the lower circuit layer 150. The adhesion layer 530may be formed of any one selected from among a die attach film (DAF), ananisotropic conductive film (ACF), a non-conductive film (NCF), ananisotropic conductive adhesive (ACA) and non-conductive adhesive (NCA).In this case, the thickness (D1) of the insulating layer may be 3˜9times that (D5) of the adhesion layer 150.

Table 2 shows experimental result data for obtaining the thickness ratioof the respective constituents of the printed circuit board according tothis embodiment. As shown in Table 2, the optimum thickness ratio of theprinted circuit board can be obtained to by measuring whether a printedcircuit board is warped or not while changing D1˜D6. In Table 2, thethickness (D1) of the insulating layer is defined as 100, and thethickness ratio of other constituents thereto is represented aspercentages to the thickness (D1).

Although Table 2 shows only representative experimental data for thepurpose of explaining an experimental method, many experiments wereconducted using other experimental data not shown in Table 2 in order toobtain the thickness ratios of the constituents defined in the presentinvention. Since Table 2 discloses the representative experimental datawithin the range in which the feature of the present invention is notobscured, the scope of the present invention is not limited to theexperimental values shown in Table 2.

TABLE 2 Thickness of Thickness Thickness Thickness of ThicknessThickness insulating of upper of lower electronic of die of layercircuit layer circuit layer component attach film prepreg Warpage No.(D1) (D2) (D3) (D4) (D5) (D6) occurrence 1 100 26 24 59 24 71 x 2 100 2522 50 20 89 x 3 100 32 26 58 19 78 x 4 100 17 17 41 17 40 ∘ 5 100 15 1345 18 30 ∘ (units: %)

From Table 2, it can be seen that when the thickness ratio proposed inthis embodiment is satisfied, the printed circuit board including theelectronic component does not warp, but when the thickness ratio thereofis not satisfied, it warps.

FIG. 14 is a drawing showing a real sample of the electroniccomponent-embedded printed circuit board (P) manufactured at thethickness ratio proposed in this embodiment. From FIG. 14, it can beseen that the printed circuit board manufactured in this way is notwarped.

As described above, the electronic component-embedded printed circuitboard according to the present invention has an optimum thickness ratioof its constituents such that the warpage thereof is minimized at thetime of manufacturing the printed circuit board. Thus, product failurecan be remarkably reduced even at the time of mass-producing theelectronic component-embedded printed circuit board.

FIGS. 4 to 8 are sectional views showing a process of manufacturing theelectronic component-embedded printed circuit board shown in FIG. 2.Hereinafter, a method of manufacturing the electronic component-embeddedprinted circuit board shown in FIG. 2 will be described in detail withreference to FIGS. 4 to 8.

First, as shown in FIG. 4, an electronic component 500 laminated with anadhesion layer 530 is attached onto a first copper foil 100 adhered on acarrier foil 130.

Subsequently, as shown in FIG. 5, the first copper foil 100 is laminatedthereon with a resin coated copper (RCC) foil composed of an insulatingresin layer 700 and a second copper foil 300. In this case, the secondcopper foil 300 is coated on one side thereof with a carrier foil 330.

Subsequently, as shown in FIG. 6, the carrier foils 130 and 330 areremoved.

Subsequently, as shown in FIG. 7, an upper circuit layer 350 and a lowercircuit layer 150, which include vias electrically connected with theelectronic component 500, are formed. Here, since a circuit formingprocess and a via forming process are performed through commonly-knowntechnologies, the detailed description thereof will be omitted.

The electronic component-embedded printed circuit board shown in FIG. 2can be manufactured through the above processes. Subsequently, as shownin FIG. 8, a solder resist layer for exposing external connectionterminals 800 may be formed. In addition, it is easily understood that afour or more layered electronic component-embedded printed circuit boardcan be manufactured by forming a build-up layer on an outer layer of theto electronic component-embedded printed circuit board.

FIGS. 9 to 13 are sectional views showing a process of manufacturing theelectronic component-embedded printed circuit board shown in FIG. 3.Hereinafter, a method of manufacturing the electronic component-embeddedprinted circuit board shown in FIG. 3 will be described in detail withreference to FIGS. 9 to 13.

First, as shown in FIG. 9, a prepreg 600 in which a space for mountingan electronic component 500 is separately provided, and the electroniccomponent 500 laminated with an adhesion layer 530 is attached onto afirst copper foil 100 adhered on a carrier foil 130.

Subsequently, as shown in FIG. 10, the prepreg 600 is placed on thefirst copper foil 100, and then the first copper foil 100 is laminatedthereon with a resin coated copper (RCC) foil composed of a resin layer700 and a second copper foil 300 such that the resin layer 730 ischarged in the space of the prepreg 600. In this case, the second copperfoil 300 is coated on one side thereof with a carrier foil 330. In thiscase, the placement of the prepreg 600 and the lamination of the RCCfoil may be performed sequentially or simultaneously.

Subsequently, as shown in FIG. 11, the carrier foils 130 and 330 areremoved.

Subsequently, as shown in FIG. 12, an upper circuit layer 350 and alower circuit layer 150, which include vias electrically connected withthe electronic component 500, are formed. Here, since a circuit formingprocess and a via forming process are performed through commonly-knowntechnologies, the detailed description thereof will be omitted.

Subsequently, as shown in FIG. 13, a solder resist layer for exposingexternal connection terminals 800 may be formed. In addition, it iseasily understood that a four or more layered electroniccomponent-embedded printed circuit board can be manufactured by forminga build-up layer on an outer layer of the electronic component-embeddedprinted circuit board.

As described above, the electronic component-embedded printed circuitboard according to the present invention has an optimum thickness ratioof its constituents such that the warpage thereof is minimized at thetime of manufacturing the printed circuit board. Thus, the productfailure of the electronic component-embedded printed circuit board canbe remarkably reduced, and the electronic component-embedded printedcircuit board can be produced in large quantities.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. An electronic component-embedded printed circuitboard comprising: a base plate including a prepreg having a space formounting an electronic component, an insulating layer having a resinlayer applied on the prepreg and charged in the space, and circuitlayers; and an electronic component mounted in the space, wherein theprepreg has a thickness 1.1˜2.5 times greater than that of theelectronic component, and the resin layer applied on the prepreg has athickness 0.2˜2.5 times greater than that of the electronic component toreduce warpage of the printed circuit board, and wherein the insulatinglayer has a thickness 1.2˜2 times greater than that of the prepreg. 2.The electronic component-embedded printed circuit board according toclaim 1, wherein the circuit layers include an upper circuit layerformed on the insulating layer and a lower circuit layer formed beneaththe insulating layer, and wherein the insulating layer has a thickness3˜22 times greater than that of the upper circuit layer, and the uppercircuit layer has a thickness 1.1˜2.6 times greater than that of thelower circuit layer.
 3. The electronic component-embedded printedcircuit board according to claim 1, further comprising: an adhesionlayer interposed between the electronic component and the lower circuitlayer, wherein the insulating layer has a thickness 3˜9 times greaterthan that of the adhesion layer.
 4. The electronic component-embeddedprinted circuit board according to claim 1, wherein the resin layer ismade of a silicon epoxy hybrid resin including NH, CH, SiH, an aromaticring, CO, Si—O—Si and Si—O—C, or an epoxy resin.
 5. The electroniccomponent-embedded printed circuit board according to claim 1, whereinthe electronic component is a silicon semiconductor device.
 6. Theelectronic component-embedded printed circuit board according to claim3, wherein the adhesion layer is formed of any one selected from among adie attach film (DAF), an anisotropic conductive film (ACF), anon-conductive film (NCF), an anisotropic conductive adhesive (ACA) andnon-conductive adhesive (NCA).